Fix occasional flicker when transitioning a property

If transitionStyleHasChangedResult is true, the code in useLayoutEffect
should run synchronously without rendering the style being transitioned
to, but this doesn't appear to be the case 100% of the time because
I've got one transition that momentarily shows the target style before
running the transition. Even this doesn't repro reliably.

Even though I'd expect returning the current style if
transitionStyleHasChangedResult is true to be a no-op (because the
useLayoutEffect should cause a synchronous render with a new value), it
doesn't seem to always be that way and this PR fixes the issue

Author: martinbooth

packages/react-strict-dom/src/native/modules/useStyleTransition.js

@@ -400,6 +400,10 @@ export function useStyleTransition(style: ReactNativeStyle): ReactNativeStyle {
     }
   }, [currentStyle, style, transitionStyleHasChangedResult]);
 
+  if (transitionStyleHasChangedResult) {
+    return currentStyle ?? style;
+  }
+
   if (
     _delay == null &&
     _duration == null &&